Pusher unit for double-cylinder knitting machines

ABSTRACT

This disclosure relates to a pusher unit for pushing knitwear downwards in double-cylinder knitting machines, which comprises two series of levers of different length arranged about a central shaft to rotate together with the needle cylinders, the lower ends of said levers being bladed, means being provided to cause the vertical sliding and oscillation of the levers along a closed endless path, the arrangement being such that in working conditions the levers are caused to penetrate into the lower cylinder and push the knitwear downwards as it is formed.

United States Patent 1151 3,640,095 Lonati 1 Feb. 8, 1972 [54] PUSHER UNIT FOR DOUBLE- FOREIGN PATENTS OR APPLICATIONS CYLINDER KNITTING MACHINES 223,282 11/1942 Switzerland ..66/l50 [72] lnventor: Francesco Lonatl, Via S. Polo ll, Brescia, 1,123,653 9 8 Great Britain-m "M66! 149 It l 6,700,185 7/1967 Netherlands ..66/l53 [22] Filed: 1969 Primary Examiner-Mervin Stein [2]] App]. No 815,670 Attorney-Guido Modiano and Albert Josif 57 ABSTRA [30] Foreign Application Priority Data rh dl l I ah CT f h k is 'sc osure re ates to a pu er unit or pus ing nitwear Dec. 2, downwards in double cyfinder i g machines which prises two series of levers of difl'erent length arranged about a [5%] :LS. (g1. ..66/147, 653/5 central shaft to rotate together with me needle cylinders he d I 66/14 147 :2 153 lower ends of said levers being bladed, means being provided [5 1 o f to cause the vertical sliding and oscillation of the levers along a closed endless path, the arrangement being such that in [56] References Cited working conditions the levers are caused to penetrate into the lower cylinder and push the knitwear downwards as it is UNITED STATES PATENTS f d onne 2,345,698 4/1944 Bromley et al ..66/ 150 3,417,581 12/1968 Docekal etal ..66/147 3Clalms,6l)nwingligures 39' Q. I K O O c 9 0 I 1 o 34 6 33 3 32 l I 8 25 I I ED 89 7 I 1 e1 7 /6 194 I v A 13 13 4 in 3 f4 f4 PATENIEDF'EB 8:912 3,6400% SHEET 1 BF 2 INVENTOR.

F RAN CESCO' LONATI PATENIEU FEB 81972 3.640.095

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IN VENTOK FRANCESCO LONATI PUSIIER UNIT FOR DOUBLE-CYLINDER KNITTING MACHINES BACKGROUND OF THE INVENTION The present invention relates to a pusher unit for articles during manufacture to be used on double-cylinder knitting machines.

It is known that in double-cylinder knitting machines, for example for the manufacture of mens stockings, pusher units are provided, acting adjacent the needles, so as to gradually push the articles downwards during their manufacture.

In particular, in automatic machines for the continuous manufacture of stockings already separated from one another, it is necessary that said devices act inside the lower cylinder adjacent the curved portion of the fixed cylindrical union, very near the needles of said cylinder.

The devices of known type generally comprise pistons or other engagement means which rotate together with the cylinders and which may be vertically displaced so as to act on the stockings adjacent the portions of the machine near the needles.

Such devices, however, give rise to some disadvantages among which may be noted a pronounced spiral twisting of the stockings due to the fact that, as they are gradually formed, they are caused to rotate about the axis of the cylinders as a consequence of the combined action of the engagement means and the rotation of the cylinders.

Another disadvantage of the known devices is constituted by the fact that said engagement means often give rise to antiaesthetic lines on the produced articles.

A further disadvantage of certain types of known device is that of an uncertain or defective working adjacent the initial portions of the stockings and during taking up phases after the formation ofthe toes and heels.

7 SUMMARY OF THE INVENTION The main object of the present invention is that of eliminating said disadvantages of the known devices by providing a pusher unit for double-cylinder knitting machines which is designed to act in the most rational and precise manner possible, by carrying out a pushing action which accompanies and efficiently displaces the fabric as it progressively forms, in uniform and regular manner on all the circumference, without giving rise to twisting or damage to the articles.

Another important object of the invention is that of providing a pusher unit which may be readily fitted to doublecylinder knitting machines of any kind.

These and still other objects, which will better appear hereinafter, are achieved by a pusher unit for double cylinder knitting machines, characterized in that it comprises a unit of rodlike levers arranged in two series of diHerent length at regular intervals about a fixed central shaft and passing longitudinally through the cavity of the upper cylinder so as to penetrate inside the top portion of the lower cylinder with their lower ends which are provided with means for the engagement of articles of knitwear being manufactured, said levers being mounted slidable, preferably in a vertical direction, parallel to the axis of said cylinders, with the possibility of oscillation, through respective guide grooves provided on a collar member arranged inside said upper cylinder and restrained thereto in relation to the operative rotation, abovesaid upper cylinder there being mounted an annular cam member designed to engage the upper portions of said levers in order to reciprocably provide them, at each rotation of said cylinders,with an oscillation and a longitudinal to-and-fro movement so that the lower end of each of said levers carries out reciprocably a substantially closed ring path with movement away from the article being manufactured, raising into a position adjacent the axis of the cylinders, moving towards said article being manufactured and subsequent lowering into a displaced position with respect to the axis of the cylinders, resilient means being provided for maintaining the engagement between the upper portions of said levers and said annulnr cam member.

BRIEF DESCRIPTION OF THE DRAWING Further characteristics and advantages of the invention will appear more clearly from the detailed description of a preferred, but not exclusive, embodiment of a pusher unit according to the invention for double-cylinder knitting machines, illustrated by way of nonlimiting example in the accompanying drawing in which:

FIG. 1 shows a perspective view of the pusher unit according to the invenn'on;

FIG. 2 is a vertical axial section of the same pusher unit in the workposition; J

FIG. 3 is a vertical axial section of the pusher unit in the rest position;

FIGS. 4a, 4b and 4c show diagrammatically, and to a reduced scale, the pusher unit in successive positions during the movement of a lever.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to such figures, the pusher unit according to the invention is fitted adjacent the internal cavities of the cylinders l and 2 of a double-cylinder knitting machine.

More precisely, the pusher unit is inserted so that it extends throughout the upper cylinder I and into the upper part of the lower cylinder 2.

According to a per se known arrangement, the movement of the cylinder 1 is provided by means of a vertical axis gear 3 which is fast with an annular platelike body 4 which rests, through bearings 5, on a fixed structure 6. This latter is provided in its upper portion with two substantially vertical rods 7 on which a transverse vertically slidable looplike member 8 designed to support the pusher unit is mounted.

The raising of the loop member 8 may be efiected by means of a forked lever 9 (FIG. 1) against the action of springs 10 mounted on the rods 7 and retained by top nuts 11. a

The loop member 8 centrally supports a vertical fixed shaft 12 which is arranged coaxial with the cylinders l and 2. Such shaft 12 extends for a certain distance inside the upper cylinder 1.

The pusher unit proper comprises a plurality of rodlike levers arranged approximately vertical around said fixed shaft 12. More precisely, in the illustrated embodiment, there is provided a series of four levers 13 arranged alternately with another four levers 14 of a second series. The levers 13 are slightly less long than the levers 14. Both the levers 13 and the levers 14 support, at their lower ends, blades 15 which are preferably of plastics material and have a toothed end portion 15a bent outwards and curved so as to contact the cylindrical fixed union 2a arranged inside the top of the lower cylinder 2.

Said levers l3 and 14 rotate together with the needle cylinders 1 and 2 and for this purpose there is provided a collar member 16 which is provided on its outer surface with a projection designed to penetrate a longitudinal groove la provided on the internal surface of the upper cylinder 1. The collar member 16 can thus be displaced upwardly with respect to the upper cylinder 1, but is constrained to rotate together with the latter. Said collar member is supported by the central shaft 12 by means of a bearing 17 and has a plurality of radial grooves 18 through which the levers l3 and 14 can slide. These latter are retained inside the grooves 18 by an annular band 19 forming part of said collar member 16. As is clearly visible in FIG. 2, the levers 13 and 14 are internally provided with projections 20 which rest on the internal portions of the grooves 18 and contact the sleeve 21 of the collar member lo 50' as to constitute fulcrurns for the oscillation of said levers, while allowing a to-and-fro displacement of the level of the latter.

Each lever 13 or 14 is made to oscillate about the fulcrum 20 and to-and-fro displaced vertically, with cyclic actuation so as to cause the movement of each lever alter another, while all the levers rotate about the fixed shaft 12.

Adjacent the top of the upper cylinder I there is secured another collar member 22 which is arranged with its axis vertical and is bored for the passage of the shall I2 nnd is further provided with a plurality of radial grooves 23 for the guiding of the levers 13 and 14.

The oscillation and alternate displacement in height movement is passed to the levers 13 and 14 by means of an annular cam member 24 which is arranged coaxial with the shaft 12 and is secured to the loop member 8. The annular member 24 has an upper fiat surface which is orthogonal to the axis of the machine and it is provided with a substantially wedge-shaped projection 24a arranged adjacent the internal edge of said annular member 24. The projection 24a constitutes a cam proper for the movement of the levers l3 and 14. The engagement between said levers and the projection 24a is achieved by means of substantially T-shaped projections 25 fixed to the top portions of said levers and projecting outwards. The shape of the projection 24a is such that, during the rotation of the levers l3 and 14 about the shaft 12, each lever is firstly made to oscillate so that the projection 25 is moved away from the axis of the machine, and is then displaced upwards and is subsequently lowered and caused to oscillate once again in the opposite direction to that in which it oscillated previously. In such manner the blade member 15 which is secured to the lower end of each lever 13 and 14 is caused to describe a substantially ringlike closed vertical path, while the fulcrum slides vertically with respect to the collar member 16.

After passing the projection 24a, each of said levers 13 and 14 returns to the maximum lowered position determined by the engagement of the relative projection 25 with the upper surface of the annular member 24.

In order to maintain the projections 25 in engagement with the upper surface of the annular member 24 and the cam projections 240, there are provided springs 26 and 27. More precisely eight springs 26 are provided which have one end secured to the projections 25 and their other end secured to a ring 28 mounted with a certain amount of play on the shaft 12.

Analogously the springs 27, eight in number, have one end secured to the projections 25 or the upper portions of the levers l3 and 14 and their other end secured to a ring 29 which rests on an annular projection 30 provided on the shaft 12, with the interposition of a counterthrust bearing 31.

Obviously, the springs 26 and 27 rotate together with the levers l3 and 14 about the fixed shaft 12.

The pusher unit may be raised to the position shown in FIG. 3, in which the blade members 15 are inside the upper cylinder 1, adjacent the lower edge thereof. Such raising must be performed at the beginning of the working of the heel and the toe of every stocking produced and every time an article being manufactured is finished. In order to raise the pusher unit it is necessary that all the blade members 15 are grouped adjacent the central shaft by moving them away from the fixed cylindrical union 2a. For such purpose there is provided a truncated cone-shaped disc 32 which is slidably mounted coaxial on the upper portion of the fixed shaft 12 and normally maintained raised due to the action of vertical springs 32a. Before raising the pusher unit, the disc 32 is lowered by means of a forked lever 33 which is pivoted in 34 onto the loop member 8. Said forked lever may be displaced, for example, by a flexible cable 35, and is designed to prevent the rotation of said disc 32. This latter, in the lowered position, engages, with its truncated cone portion, the upper ends of the levers 13 and 14 which are conveniently tapered at 36.

The tapered portions 36 slide on the disc 32 which simultaneously causes the levers l3 and 14 to assume the positions shown in FIG. 3 with the blade members 15 arranged grouped together.

In this situation, the pusher unit can be raised by acting on the forked lever 9 so as to raise the loop member 8, thus compressing the springs 10 carried by the rods 7.

In the raised position of the pusher unit the levers 13 and 14 continue to rotate and reciprocably displace up and down, but they no longer oscillate about the fulcrums 20 due to their engagement with the disc 32.

The working of the pusher unit according to the invention is as follows.

Before the beginning of the manufacture of a stocking, the pusher unit is arranged as shown in FIG. 3, that is with the blades 15 grouped and raised inside the upper cylinder 1.

As soon as the manufacture of a stocking begins, the disc 32 is disengaged from the levers 13 and 14 by raising said disc by means of the forked lever 33. Alter this the forked lever 9 is released so as to permit the lowering of the pusher unit due to gravity and the action of the springs 10.

In such manner the blade members 15 widen and lower towards the upper curved portion 2b of the cylindrical fixed union 2a in position that is very near to the needles of the lower cylinder 2. The pushing action of the unit is thus carried out directly adjacent the first links forming the fabric of the stocking being manufactured, after which the pusher unit continues to move downwards until it reaches the position shown in FIG. 2 in which the blade members engage the internal cylindrical surface of the fixed union 2a.

Both during the lowering and after reaching the lowermost position (shown in FIG. 2), the pusher unit continues to act inside the tubular fabric being formed, along all the circumference of the latter, by means of the blade members 15 which displace one after another, as is diagrammatically shown in FIGS. 4a, 4b and 4c. The displacement, which takes place as a result of the engagement of the projections 25 with the cam 24a consists in a backward movement of the blade member 15 considered (with respect to the internal surface of the fixed union 20) followed by a raising (FIGS. 44 and 4b). Subsequently the same blade member 15 is once again displaced outwards so as to engage the inside of the fabric being fonned and is then lowered to the starting position, as indicated with dotted lines in FIG. 4c.

In such manner the blade members 15 act one after another to push the material being formed downwards by acting alternately on all the circumference and in zones of different height. In fact first of all a lever 13 will act, then a lever 14, then again a lever 13 and then a lever 14, and so on following one after another.

As may be noted the pusher unit according to the invention acts in very uniform manner on the tubular fabric being formed, pushing the latter downwards in a continuous manner without causing any twisting of the fabric of other similar defects.

The invention as thus conceived may be subject to numerous modifications and variations, all lying within the scope of the inventive concept.

In practice the materials employed, as well as the dimensions, may be varied according to needs and, moreover, all the members may be replaced with other technically equivalent means.

I claim:

1. In a double-cylinder knitting machine, having an upper and a lower needle cylinder, a pusher unit comprising a substantially vertical shaft coaxial with the needle cylinders of the machine, a plurality of rodlike levers within the upper needle cylinder and arranged around said shaft and movable in substantially vertical direction with an oscillating movement component, means at the lower ends of said rodlike levers capable of penetrating in the cavity of the lower needle cylinder for engaging and pushing the fabric during its manufacturing, an annular cam member near the upper ends of said rodlike levers and cooperating with said ends to cause said levers to move, an annular grooved member for guiding said rodlike levers, retaining means in engagement with said rodlike levers and means for raising the levers to a position spaced from the lower cylinder, wherein according to the improvement, the pusher unit comprises further, in an intermediate position of the length of said rodlike levers, a collar member, said collar member having radial grooves for slidably receiving a portion of said levers, said levers having each a radial projection at said portion thereof, said grooves having at least one inner surface in engagement with said radial projection of said levers, said radial projections acting thereby as fulcrums for the oscillation of said levers.

2. A pusher unit according to claim 1, wherein said rodlike levers have upper ends tapered on the inner side, and the pusher unit further comprises a disc with a substantially truncated cone-shaped surface mounted above said levers and displaceable in height for engaging said tapered upper ends dur- 5 

1. In a double-cylinder knitting machine, having an upper and a lower needle cylinder, a pusher unit comprising a substantially vertical shaft coaxial with the needle cylinders of the machine, a plurality of rodlike levers within the upper needle cylinder and arranged around said shaft and movable in substantially vertical direction with an oscillating movement component, means at the lower ends of said rodlike levers capable of penetrating in the cavity of the lower needle cylinder for engaging and pushing the fabric during its manufacturing, an annular cam member near the upper ends of said rodlike levers and cooperating with said ends to cause said levers to move, an annular grooved member for guiding said rodlike levers, retaining means in engagement with said rodlike levers and means for raising the levers to a position spaced from the lower cylinder, wherein according to the improvement, the pusher unit comprises further, in an intermediate position of the length of said rodlike levers, a collar member, said collar member having radial grooves for slidably receiving a portion of said levers, said levers having each a radial projection at said portion thereof, said grooves having at least one inner surface in engagement with said radial projection of said levers, said radial projections acting thereby as fulcrums for the oscillation of said levers.
 2. A pusher unit according to claim 1, wherein said rodlike levers have upper ends tapered on the inner side, and the pusher unit further comprises a disc with a substantially truncated cone-shaped surface mounted above said levers and displaceable in height for engaging said tapered upper ends during the inoperative phase of said levers.
 3. A pusher unit according to claim 1, wherein said collar member has means allowing displacement thereof in height with respect to said upper needle cylinder. 